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CVE-2026-65400 Apple CVE debrief

Apple macOS Improper Authentication Vulnerability debrief. This critical vulnerability affects macOS systems, allowing potential attackers to bypass authentication mechanisms. macOS administrators and security teams must verify authentication mechanisms, assess exposure, and prioritize patching based on CISA guidance. The vulnerability has a CVSS score of 9.8, indicating a high severity level. Immediate attention is required to mitigate potential risks. Affected product deployments should be identified, and owners assigned for follow-up. Official advisories and CVE records should be reviewed to validate affected scope, severity, and vendor guidance.

Vendor
Apple
Product
macOS
CVSS
CRITICAL 9.8
CISA KEV
Listed
Original CVE published
2026-08-18
Original CVE updated
2026-08-18
Advisory published
2026-08-18
Advisory updated
2026-08-18

Who should care

macOS administrators and security teams should be aware of this critical vulnerability. They must verify authentication mechanisms, assess exposure, and prioritize patching based on CISA guidance. Affected operators, platforms, and security teams are impacted by this vulnerability, requiring immediate attention to mitigate potential risks.

Why it matters

This vulnerability requires immediate attention from macOS administrators and security teams due to its critical severity and potential for exploitation.

  • Verify authentication mechanisms on macOS systems
  • Assess exposure and prioritize patching based on CISA guidance

Technical summary

Apple macOS Improper Authentication Vulnerability with a CVSS score of 9.8. This critical vulnerability affects macOS systems, allowing potential attackers to bypass authentication mechanisms. The vulnerability requires immediate attention from macOS administrators and security teams. Verify authentication mechanisms on macOS systems and assess exposure to prioritize patching based on CISA guidance.

Defensive priority

High priority for macOS administrators and security teams

Recommended defensive actions

  • Apply mitigations in accordance with vendor instructions
  • Ensure compliance with CISA’s BOD 26-04 guidance
  • Evaluate each asset's internet exposure and adhere to BOD 26-04 patching guidelines

Evidence notes

The CISA Known Exploited Vulnerabilities catalog and CVE Program record provide official details on this vulnerability. The CVE record was published on 2026-08-18T00:00:00.000Z and has not been modified since then. Evidence is limited to publicly available information from these sources. Defenders should verify affected scope and vendor guidance while prioritizing patching based on CISA’s BOD 26-04 guidance.

Sources and references

Verified primary and authoritative sources

  • CVE-2026-65400 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-65400

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-65400 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-65400

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

  • CISA Known Exploited Vulnerabilities catalog

    Publisher, destination, and source semantics verified

    URL: https://www.cisa.gov/known-exploited-vulnerabilities-catalog

    Cybersecurity and Infrastructure Security Agency - Official CISA catalog of vulnerabilities known to be exploited in the wild.

Supplemental references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.